They have to inject themselves, often up to five times a day. But there are now hopes for an end to the daily jab of insulin for diabetics. James Meikle reports.
Richard Lane, a 61-year-old from Bromley, Kent, will soon cast off his near-30-year dependence on insulin, which is needed to fight the insidious shortage of the natural hormone that would normally help turn glucose in his blood into energy for his cells. In doing so, he will become the first patient in Britain to dispense fully with artificial insulin.
His treatment stems from a procedure developed in Edmonton, Canada, in the late 1990s by British-born surgeon James Shapiro. The procedure is still very much in its practical infancy: two patients have tried the treatment in Britain before him, but with only partial success.
Thousands of cells have been harvested from the pancreases of dead organ donors and, while he is under sedation and a local anaesthetic, injected through Lane's side into a vein in his liver. There they have developed their own blood supply and begun producing insulin.
The procedure, according to his doctor, Prof Stephanie Amiel, is a "hugely exciting breakthrough. The implications for the future are enormous. Eventually this could mean the end of insulin dependence for all type 1 diabetes sufferers."
Lane has had three procedures over four months at King's College Hospital, London, each lasting around 45 minutes. The treatment should allow him to loosen the tight regime of self-blood testing, self-injecting and dietary rectitude all patients with type 1 diabetes must follow to stave off the complications, which range from confusion, nausea and loss of consciousness to eye problems, renal failure, amputation and heart disease.
In this type of diabetes - responsible for about a fifth of all diabetes cases - islet cells in the pancreas are destroyed by the body's immune system. For a quarter of a century, scientists have been attempting to transplant them, but it was not until Shapiro's team cracked some of the problems by sharply increasing the number of transplanted cells and using different types of anti-rejection drug that progress was made.
There are still drawbacks, especially the lifelong reliance on those anti-rejection drugs and the problems caused by a severe shortage of pancreases, with about 800 donated annually in Britain.
Few organs are suitable for harvesting cells as many of those donated are needed for full organ transplants or come from diabetic patients whose kidneys have also failed.
But scientists hope that the overall drug cocktail will be reduced and that islet cells, perhaps using stem cells, can be taught to trick the body into producing more of its own, thus eking out short supplies.
Alternatively, more islet cells might be grown in the lab. Vaccines could prevent the body from attacking new islet cells.
At present, it is those most at risk of hypoglycaemia, a potentially coma-inducing condition, who will benefit most. Such "hypo" attacks usually occur because the patient has given him or herself too much insulin in relation to food intake, making glucose levels in the blood dive too far to support normal brain function.
Progress here has been slower than hoped four years ago by some enthusiasts who suggested islet cell transplant might prove the biggest breakthrough since the discovery of insulin in the 1920s.
Some Canadian patients are back on artificial insulin once more. The two previous patients who underwent the procedure at King's College Hospital have experienced partially successful results, winning relief from their hypos but still requiring small doses of insulin.
Prof Amiel says: "In the current state of technology, islet transplantation is not perfect. We do not have enough organ donors, therefore we cannot extract enough islets to help all type 1 patients. More research is needed to perfect the islet isolation procedures and the drugs we use to prevent rejection of the islets and recurrence of the diabetes. At present, we can therefore only offer this treatment to patients in whom conventional treatments are failing in a major way."
Few centres can offer the multidisciplinary expertise needed, combining specialists in diabetes, liver transplantation, cell isolation and radiology. However, a total of nine are involved in a consortium backed by the charity Diabetes UK for a research programme, which is at present limited to patients with recurrent hypos.
Four years ago it raised £250,000 (€173,875) to fund the first 10 islet cell transplants. The first three have cost around £35,000 each, while the centres find their own funding for all the other costs.
Data from 10 successful transplants will be needed for the procedure to be recognised and funded as a therapy, which could help increase its availability.
Some estimates suggest organ shortage may mean this could help at first only around 400 people a year.
Angela Wilson, the charity's director of research, says it is now funding work "which we hope will turn this breakthrough into a cure for all people with the condition. The transplant work is moving forward all the time."
Meanwhile, things are moving apace elsewhere. Shapiro and a team of surgeons at Kyoto University hospital have recently taken islets from a healthy living woman and transferred them to her 27-year-old daughter.
However, many specialists are cautious about this development, suggesting the donor might end up a diabetic herself since she might have lost too many of her own insulin-producing cells.